mchess-client/lib/chessapp/chess_utils.dart

import 'package:flutter/material.dart';
import 'package:flutter_svg/svg.dart';
import 'package:quiver/core.dart';

enum ChessPieceName {
  none,
  whitePawn,
  whiteBishop,
  whiteKnight,
  whiteRook,
  whiteQueen,
  whiteKing,
  blackPawn,
  blackBishop,
  blackKnight,
  blackRook,
  blackQueen,
  blackKing,
}

enum ChessColor { black, white }

Map<ChessPieceName, String> chessPiecesAssets = {
  ChessPieceName.whitePawn: 'assets/pieces/white/pawn.svg',
  ChessPieceName.whiteBishop: 'assets/pieces/white/bishop.svg',
  ChessPieceName.whiteKnight: 'assets/pieces/white/knight.svg',
  ChessPieceName.whiteRook: 'assets/pieces/white/rook.svg',
  ChessPieceName.whiteQueen: 'assets/pieces/white/queen.svg',
  ChessPieceName.whiteKing: 'assets/pieces/white/king.svg',
  ChessPieceName.blackPawn: 'assets/pieces/black/pawn.svg',
  ChessPieceName.blackBishop: 'assets/pieces/black/bishop.svg',
  ChessPieceName.blackKnight: 'assets/pieces/black/knight.svg',
  ChessPieceName.blackRook: 'assets/pieces/black/rook.svg',
  ChessPieceName.blackQueen: 'assets/pieces/black/queen.svg',
  ChessPieceName.blackKing: 'assets/pieces/black/king.svg',
  ChessPieceName.none: 'assets/empty.svg',
};

class ChessCoordinate {
  final int column;
  final int row;

  ChessCoordinate(this.column, this.row);

  factory ChessCoordinate.fromString(String coordString) {
    var column = int.parse(coordString[0]);
    var row = int.parse(coordString[1]);

    return ChessCoordinate(column, row);
  }

  ChessCoordinate.copyFrom(ChessCoordinate original)
      : column = original.column,
        row = original.row;

  static String columnIntToColumnString(int col) {
    String colStr;

    colStr = String.fromCharCode(col + 96);

    return colStr;
  }

  static int columnStringToColumnInt(String col) {
    int colInt;
    colInt = col.codeUnitAt(0) - 96;
    return colInt;
  }

  @override
  String toString() {
    String rowStr = row.toString();
    String colStr = column.toString();

    return '$colStr$rowStr';
  }

  @override
  operator ==(other) {
    return other is ChessCoordinate &&
        other.column == column &&
        other.row == row;
  }

  @override
  int get hashCode {
    return hash2(column, row);
  }
}

class ChessPiece extends StatelessWidget {
  final ChessColor color;
  final ChessPieceName pieceName;
  final Widget? pieceImage;

  const ChessPiece._(this.pieceName, this.color, this.pieceImage);

  factory ChessPiece(ChessPieceName name, ChessColor color) {
    Widget? pieceImage;
    String pieceAssetUrl = chessPiecesAssets[name]!;

    pieceImage = SvgPicture.asset(pieceAssetUrl);
    return ChessPiece._(name, color, pieceImage);
  }

  const ChessPiece.none({super.key})
      : pieceName = ChessPieceName.none,
        color = ChessColor.white,
        pieceImage = null;

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      child: pieceImage,
    );
  }
}

class ChessMove {
  ChessCoordinate startSquare;
  ChessCoordinate endSquare;
  ChessPiece? movedPiece;
  ChessPiece? pieceOnEndSquare;

  ChessMove(this.startSquare, this.endSquare, this.movedPiece);
}